Copy vs View

Array Copy

copy creates a duplicate of the original array with all its elements intact. Any changes made to it doesn’t affect the original array.

arr = np.array(["Shame", "Hangin'", "Glory", "My Blood"])
new_arr = arr.copy()
new_arr[1] = "Hit It"
print(arr) # ['Shame' "Hangin'" 'Glory' 'My Blood']
print(new_arr) # ['Shame' 'Hit It' 'Glory' 'My Blood']

Use copy if you don’t want the original array to be affected.

Array view

view lets you create a view of the original array. Changes made to the view will affect the original array and vice versa.

arr = np.array(["Shame", "Hangin'", "Glory", "My Blood"])
new_arr = arr.copy()
new_arr[1] = "Hit It"
print(arr) # ['Shame' "Hangin'" 'Glory' 'My Blood']
print(new_arr) # ['Shame' 'Hit It' 'Glory' 'My Blood']

Use view if you wish to save memory.

`base`

It returns None if the array is a copy. If not, it refers the original array.

arr = np.array([1,2,3])
x = arr.copy()
y = arr.view()

print(x.base) # None
print(y.base) # [1 2 3]

z = x.copy()
print(z.base) # None

w = y.view()
w[0] = 100
print(w.base) # [100   2   3]